In any relationship, there's a fine line between passion and control. Here's how to tell the difference. And how to protect yourself.

His words hurt more than you think

His words hurt more than you think

In one study, 77% of college women copped to being, or having been, in an abusive relationship. Experts don't have a single, set definition for emotional or psychological abuse, but it's generally described as any behavior—short of physical violence—used to manipulate, degrade, humiliate, or punish another person. This can be extreme Lifetime movie stuff: threats, stalking, vandalism, phone or email monitoring. But, just as often, it can be more subtle: overreactions that keep you walking on eggshells, underhanded compliments, barbed advice that's allegedly for your own good, even offers to "help" by managing your money, career, or relationships with others.

Most of these relationships won't escalate to physical violence. But some will and it's difficult to tell until it's too late. The best thing you can do for yourself—or for a friend you suspect might be in such a situation—is to know the warning signs. Here are four actions you might be tempted to write off as annoying or insensitive but experts say are serious red flags.

He wants you all the time

He wants you all the time

One reader told us that her boyfriend would always pressure her into having sex with him, even when she'd say she didn't want to. This comes in different forms: pressuring you to send naked pictures, have unprotected sex, or any other sexual behavior. It can also be a boyfriend who just happens to show up anytime you want to be alone or with friends, or the guy that won't stop calling your phone. He doesn't accept your personal boundaries which is dangerous because if you ever try to leave, the threat of losing control sends him over the edge.